Doxy can upset the stomach. Good news is that her platelets are on the upswing! Is she on pred too?
Which med did they give you? Carafate or sulcrafate?
Annie just finished 8 weeks of doxy. We ended up feeding her EVO canned (and kibble) and fried turkey and hand fed her. She got, in addition to the doxy, carafate, Quiet Digestion (a chinese herbal med) and zantac and milk thistle.